Lawrence Lokken (Florida) has posted Effects of Losses on the Credit for Foreign Income Taxes on SSRN.  Here is the abstract:

Under US tax law, a US resident (e.g., a domestic corporation) is allowed credit against US tax for foreign income taxes, but the credit may not exceed US tax, before credit, on income from foreign sources. This credit limitation is calculated separately for foreign income taxes on passive income, on the one hand, and other (general limitation) income, on the other. To preserve the long-run integrity of these separate limitations, Congress has adopted three sets of rules requiring recapture of losses. The underlying idea is that if loss in one category offsets income in another category, the loss should be recaptured by recharacterizing subsequent income of the loss category as income of the category offset by the loss. Each of the three loss rules is complex, but interactions of the three rules are stunningly complex. The Treasury, in December of 2007, issued regulations on the loss rules, devoting special attention to interactions among them. This paper explains and illustrates the new regulations.